[Brilliant Diamond & Shining Pearl] Will competitive move to BDSP?

This is something I often think about when this game comes to mind, I personally genuinely hate the competitive online in sword and shield mostly due to Dynamax, do you guys believe that some Pokemon that didn't appear in the original diamond and pearl will appear in this game in addition to having VGC and other competitive formats to move to this game? If you think yes, do you like this decision yes or no?

I think that BDSP will have its own competitive scene yeah. The question though is whether or not SwSh and BDSP will be able to battle with each other or not, they might not be allowed to connect with each other. If they can, then there likely will be one meta for Gen 8. If not, then there may be separate scenes.

I think BDSP will not have any competition related battles, like VGC or ranked, only free online battles.
Why?
Because it would split the competitive players between BDSP and SwSh.
Unless dynamax and everything else from SwSh are present in BDSP, which I don't think it's going to happen.

Sadly during the direct think it was near the end it did say it would be saying in sword and shield

during the direct they said it stays on sword and shield and tbh i wasn't surprised by that. it was pretty clean to me that on these remakes only gen1 to gen4 pokemons will be available. Competitive staying in sword and shiled is kinda the proof imo

When they dropped ORAS, they expanded competitive from X/Y to envelope both games.

They did this by updating the Hoenn region to be more "modern" to justify the new mega stones existing.

They said BDSP would be a "faithful remake" essentially letting us know that what happened with ORAS wouldn't be happening. I don't think they can make what is considered a "faithful remake" while simultaneously updating the region in a way to support dynamaxing that isn't just shoe-horned in.

So coupling this with the fact that other people are saying they've already decided to keep it in S/S is a safe bet that it's true.

I personally don't see what's wrong with splitting the competitive scene, lets go Pikachu and Eevee had its own competitive meta even if it only existed on smogon, it wouldn't be a bad thing for it to have it's own scene especially when it has a completely different scene and sets of Pokémon.

It was confirmed that the Official Rankings and Online play would be staying with Pokemon Sword and Shield. BDSP will not have its own and probably won't even get much thought put into in when it comes to updates, unless it is a serious bug. So don't expect it.

Hardly, unless everything from Gen 8 is added to the game. If this was the case, they would have already released some information about it.